292 Dr. P. L. Sclater on the Birds of the Comuro Islands. 



rences of rare and accidental visitors in my note-book since my 

 list went to press : — 



Strix otus. — A third specimen of this common European Owl, 

 but which appears to be only an accidental visitor to Malta, was 

 taken on the 17th December last, and is now in my possession. 



Passer petronia. — Another example of this species, which, I 

 am informed, is very common in Naples, where it is taken in 

 nets in great numbers, and migrates in spring and autumn, was 

 captured alive in February this year (1864), and is in the pos- 

 session of Dr. Gulia. 



Emberiza cirlus. — I obtained another example, taken alive in 

 1863. 



Hirundo rupestris. — This Swallow appears to be less given to 

 roaming than any of its congeners, and it has even been doubted 

 whether it is a migrant at all. It may perhaps be for this reason 

 that we seldom see 'it here, whilst the other species, H. rustica 

 and H. urbica, are plentiful during the migratory seasons. My 

 first acquaintance with H. rupesti-is in these islands was in De- 

 cember last, when spending a day in Gozo. There were several 

 of them flying over the town and along the fronts of the houses 

 in the streets, and round the ditch of the old fortifications, which 

 is used as a fruit- and vegetable-garden. The day was cold, but 

 clear. On revisiting the island about a month afterwards, on 

 the 26th January, I again met with them the first thing on 

 landing. On neither occasion was any other species to be seen, 

 nor do any of the Swallows or Swifts generally winter here. 

 Again, at the interval of about another month (on the 20th of 

 February), I observed a specimen in the Malta market. All this 

 serves to prove the sedentary tendency of the H. rupestris ; but 

 that it does sometimes migrate there can be no doubt. 



XXIII. — On the Birds of the Comoro Islands. 

 By P. L. Sclater, M.A., Ph.D., F.R.S., &c. 



(Plate VII.) 



The Comoros are a group of four islands lying in the northern 

 part of the Mozambique Channel, between Madagascar and the 



